Core taking device



y 1940- M. SCHLUMBERGER 2.2 .683

I CORE TAKING DEVICE Filed Jan. 24, 1936 Patented May 14, 1940 PATENT .QFFICE CORE TAKING DEVICE Marcel Schlumberger, Paris, France, assignor to Socit de Prospection Electrique, Procdes Schlumberger, Paris, France, a corporation of France Application January 24, 1936, Serial No. 60,726 In France November 16, 1935 2 Claims.

In boring and other operations during the working of petroleum beds, frequent occasion arises for forcing projectiles by means of guns of special construction into the lateral walls of the bore holes.

This is particularly the case when it is intended to take samples by means of a projectile such as described in my United States application Serial No. 54,340, filed December 13, 1935, for a Core 0 taking device, which has matured into Patent No.

2,055,506, dated September 29, 1936. The result to be accomplished is the forceful discharge into the adjacent wall of a bore hole of hollow projectiles which are connected with the guns by means of a flexible connection and which, when they penetrate the walls of the bore hole, are filled with the substance thereof. By hauling up the gun and the projectile which remains connected with the same through the flexible connection and bringing them above ground, a sample or core of the said substance is obtained.

This is also the case when it is intended, by means of a so-called bullet perforator, to perforate the wall of bore holes, which are lined with a casing and cemented, in order to cause the inner part of the bore hole to communicate with the underground petroleum.

The initial velocities imparted to the projectiles must then be sufficient to force the said projectiles through one or more thicknesses of steel tube as well as through a thickness of several centimeters of cement.

In both cases, as also whenever it is intended to discharge projectiles laterally in the bore holes, the difficulty lies in the fact that as the bore holes have often diameters of less than 15 centimeters, the guns must be very short, say of the order of only a few centimeters.

If the explosive chamber were placed rearwards of the projectile, as in ordinary guns, the length of the tube of the gun, through which the projectile must pass, would be correspondingly shortened. Therefore in order to give the projectile the desired initial velocity, it would be necessary to use excessive quantities of explosives. Furthermore it is generally impossible to employ such an arrangement when the projectile itself must be rather long, as is the case with the bullet sample-taking devices.

It has been already proposed, in order to avoid this dimculty, to arrange the explosion chamber alongside of the gun and so that it communicates with the bore of the latter through a rather wide opening. This arrangement has the disadvantage that the passage of the deflagration gases is necessarily restricted before they enter the tube behind the projectile and that the velocity of these gases is, therefore substantially reduced. Hence they cannot act with all their expansive force. Furthermore, the stresses caused by the explosion of these gases are exerted in an asymmetrical manner.

One object of the present invention is to obviate these inconveniences, while obtaining a maximum length of way for the ejection of the projectile. Another object is to provide an ejection system as simple as possible, reliably as to its operation, easy to make and the use of which is comparatively inexpensive.

The invention consists essentially in arranging the explosion chamber annularly around the gun or around the projectile.

As to the gun itself, particularly in the case of bullet perforators, it can be formed of a tube of special steel which is highly resistant to compression and which may be inserted laterally, into the cavity in the block formed by the perforating device. The space between the walls of this tube and the lateral walls of the cavity into which it is inserted forms the annular explosion chamber.

This arrangement is of advantage in that it permits an extremely easy machining of the device and therefore the use of steel having an extremely high resistance, that being a security factor. On the other hand, since the parts which wear most quickly are the tubes of the gun, these tubes can be easily replaced when worn out without it being necessary to change the body of the perforator device itself, thereby accomplishing a saving in operating cost.

In the appended drawing two embodiments of the invention are shown by way of non-limitative examples.

In this drawing Fig. 1 is a diagrammatical longitudinal sectional view of a perforator with a plurality of guns according to the invention.

Fig. 2 is a diagrammatical longitudinal sectional view of another embodiment of the invention.

Fig. 3 is a cross sectional view on line 33 of Figure 2.

In Figure 1, I is the cylindrical body of the perforator device which comprises, as is usual, an assembly of guns arranged one above another and the axes of which are preferably arranged angularly each with respect to the others.

This perforator body I, which is made of steel having a high resistance, is provided with a numher of cavities 2 which form the explosion chambers. Into these cavities are screwed or inserted in any other manner the gun tubes 3 which are made of a steel highly resistant tocompression. Each gun tube 3 extends somewhat more than three quarters of the width of the body of the perforator, which is evidently the maximum length permissible therefor. A packing ring 4 securely seals the explosion chamber. The tube 3 does not fill the cavity 2, the latter being of such dimensions as to provide an annular space which forms, as above stated, the explosion chamber.

5 is the projectile resting at its rear end against the bottom of the cavity 2. This DIO? jectile is provided with a guide-ring 6 for its passage through the tube of the gun. The annular member 6 fulfills the office of the waist usually provided on artillery munitions. By the explosion said member 6 is almost completely crushed between the tube and the projectile and its function is that of a seal.

In Figure 2, I is the body of the device in which are bored one above another horizontal holes 8 which form the tubes of the guns serving to eject sample-taking projectiles 9. These projectiles themselves are formed of hollow cylindrical tubes which are closed in their rear ends and are connected with the guns through a flexible connection formed, for instance, of two cables I0 (Figure 3); these cables serve, as is known, to draw the projectile after its ejection, out of the formation wall into which it has penetrated.

In the rear part of each bore 8 is provided in the material of the body I an explosion chamber ll into which the rear end. of the projectile 9 extends. Explosion chamber H, which is of annular form, entirely surrounds the rear part of the projectile when the latter is in position for firing.

In either embodiment of the invention (Fig. 1 or Figs. 2 and 3) the firing of the explosive charge contained in the chamber (2 or II) can be effected in any suitable manner, as for instance by means of fusible filaments l2 (Fig. 2) inserted into the explosion in these chambers and heated by the passage of an electric current.

It is evident that by means of the invention, exemplified by the several embodiments described above and which is susceptible of other embodiments, a maximum length of traverse for the projectile and consequently -a maximum of sustained pressure from the gases of explosion before the discharge of the projectile from the mouth of the gun are obtained, without any diminution of the explosive energy of the charge, as by the throttling eil'ect of a constricted passage way for said gases.

- Of course, many changes can be made in the devices which are shown in the drawing, without departing from the scope of the invention.

Furthermore, the invention is applicable not only to the particular cases and uses herein tie-'- scribed, but to all cases and uses wherein it is desired to employ a gun (using that word in its broadest sense) which must needs be much abbreviated as to its length. The invention is, however, of special utility in the operation of discharging projectiles within a bore-hole.

What I claim is:

1. A device for shooting a projectile within a bore hole, comprising a body adapted to be lowered or placed in said bore hole and having a combustion or powder chamber therein, a firing tube adapted to chamber a projectile, said tube projecting into said chamber with the inner end spaced from a wall of said chamber and its outer end secured to a. wall of said chamber and substantially fiush with the outer wall of said body, and means for igniting powder in said chamber.

2. A device for shooting a projectile within a bore hole, comprising a body adapted to be lowered or placed .in said bore hole and having a combustion or powder chamber therein, a firing tube adapted to chamber a projectile, said tube projecting into said chamber with the inner end spaced from a wall of said chamber and its outer end secured to a wall of said chamber, and means for igniting powder in said chamber.

MARCE'L SCIHJUMBERGER. 

